The average of 100 children per annum attending Red Cross War Memorial Children's Hospital 9RCWMCH) with the diagnosis of kerosene ingestion would give a sample of 200 children over a two-year period, with 100 patients in each group. From a postulated secondary infection rate of 15 to 50% for children not receiving an antibiotic, a midway point of 25% estimated the treatment failure rate in the placebo group. With no information available on the treatment failure rate in the active group, failure rates of 10% and 5% were arbitrarily applied. With 25% and 5% treatment failure rates for placebo and active groups respectively, at a level of significance of α = 0.05 a sample size of 100 per group gives a power of 0.98 and with failure rates of 25% and 10% a power of 0.80.